1. Related Applications
This application is an improvement in my copending application Ser. No. 06/836,285 filed 5 March 1986 for "Text Orientation System For Dot Matrix Printers".
2. Field of the Invention
The present invention relates to apparatus for rotating characters of the type generated by character generators in any desired image font or format. More particularly, the present invention relates to a novel high speed circuit for rotating a character, micro column word by by micro column word as it is generated or read out of a character generator memory.
3. Description of the Prior Art
In my aforementioned copending application Ser. No. 06/836,285, a complete form called a logical page could be generated and the logical page could be rotated 90.degree., 180.degree. or 270.degree. from the zero position. The logical circuitry employed to make the transformation or rotation of a logical page required that two complete characters be stored in a character matrix format in a character generator memory oriented 90.degree. from each other. By storing whole characters, the characters could be scanned or read out of the memory buffer at high speed so that information being read out of memory could be accomplished at speeds sufficiently high to supply information for a laser printer or a laser printer engine. A second purpose for using two rotated characters in the character generator memory made it possible to flip or rotate either character being read out of memory by 180.degree. so that the two stored characters provided the means for presenting the two characters in one of four rotational positions.
The character generator memory in this prior art reference was found to be commercially successful and reliable even though approximately 5,000 bits of memory are utilized for each 50 bit character to be generated. It is well known that thousands of characters are provided with laser printers and the cost of the character generator memory is substantially doubled when characters are stored in two rotational positions.
It would be desirable to maintain a laser printer or dot matrix printer system of the type disclosed in my copending application with the same number of characters in the character generator employing less character generator memory.